def main():
    S = input()

    i = len(S)
    road = [2 ** i, 2 ** i * 2 - 1]
    for s in S:
        if s == 'L':
            road = [road[0], (road[0] + road[1]) // 2]
        else:
            road = [(road[0] + road[1]) // 2 + 1, road[1]]

    print(road[0])

main()